Core box drawing apparatus



Dec. 10, 1957 w. E. HEDDERICH CORE Box DRAWING APPARATUS 6 Sheets-Sheet 1 Filed Jan. 12, 1954 ijf uvam-volk; Wallin 6. CNecldev-ck fj CA-viven Dec. 10, 1957 w, E, HEDDERICH 2,815,547

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CORE Box DRAWING APPARATUS Filed Jan. 12, 19514v 6 Sheets-Sheet 6 m Mullen q'leev'ich MAJ'fJJ/Q 2,8 l ,54 'L7 Patented Dec. l ll 957 fire CURE BOX DRAWING APPARATUS William E. Hedderich, Rockford, lll., assigner to Greenlee Bros. & Co., Rockford, Ill., a corporation of illinois Application January 12, 1954, Serial No. 403,609

12 Claims. (Cl. 22-10) This invention relates generally to apparatus for handling sand lled core boxes in foundries and, more particularly, to core box drawing apparatus in which the core and the box are supported on a horizontally disposed core plate or bottom board and the box is separated from the core by moving the box and the plate vertically relative to and away from each other to leave the core resting on the plate.

One object of the invention is to provide improved core box drawing apparatus in which core boxes of widely differing sizes and shapes and varying positions relative to the apparatus may be drawn quickly and easily without disturbance of the packed sand forming the cores therein.

Another object is to hold each box securely without horizontal shifting thereof during a drawing operation by a plurality of clamping jaws which are `adjustable individually and different distances into engagement with opposits sides of each box to compensate for different shapes of boxes and different positions thereof relative to the apparatus.

A further object is to avoid jarring of each core box during the clamping operation by applying to each jaw a relatively small force for shifting the jaw into engagement with the box-and a substantially larger force to clamp the box rigidly between the jaws.

A more detailed object is to grip each core box between a plurality of opposed clamping jaws which are movable individually along horizontally spaced paths and in pairs transversely of the paths to accommodate boxes of different lengths.

The invention also resides in the novel construction and arrangement of the actuating mechanism for each jaw to enable a large clamping force to be applied to the latter by a power actuator having a working stroke shorter than the range of movement of the jaw.

Other objects and advantages of the invention will become apparent from the following detailed description taken in connection with the accompanying drawings, in which Figure l is a side elevational View of core box drawing apparatus embodying the novel features of the present invention.

Fig. 2 is a plan View of the apparatus.

Fig. 3 is an enlarged fragmentary sectional view taken along the line 3 3 of Fig. 1.

Fig. 4 is a reduced fragmentary sectional View taken along the line 4 4 of Fig. 7.

Figs. 5 and 6 are enlarged fragmentary sectional views taken along the lines 5-5 and 6-6 respectively of Fig. 3.

Fig, 7 is a fragmentary sectional View taken along the line 7 7 of Fig. 5.

Fig. 8 is a fragmentary sectional View taken along the line 8-8 of Fig. 6.

Fig. 9 is an enlarged fragmentary sectional View taken along the line 9--9 of Fig. 2.

Fig. 10 is a perspective view of part of the actuating mechanism for one jaw.

Figs. ll and l2 are enlarged fragmentary sectional views taken along the lines 11-11 and 12-12 of Fig. 2.

Fig. 13 is a diagrammatic view showing the fluid pressure circuits for the actuating mechanism of one pair of jaws.

Fig. 14 is an elevational view of a control panel for the apparatus.

While the invention is susceptible of vaiious modifications and alternative constructions, I have shown in the drawings and will herein describe in detail the preferred embodiment. It is to be understood, however, that I do not intend to limit the invention by such disclosure, but aim to cover all modifications and alternative constructions falling within the spirit and scope of the invention as expressed in the appended claims.

In the drawings, the invention is shown for purposes of illustration embodied in apparatus which is especially adapted for use in foundries to draw or separate a core or pattern box 15 from a core (not shown) of tightly packed sand formed in the box. Such boxes usually are shallow and open-topped with a slight interior draft to facilitate withdrawal of the core from the box and may vary widely in exterior shape depending on the shape of the cores to be formed therein. After sand has been packed tightly in the box and the top of the sand has been leveled, the sand and the box are covered with a at core plate or bottom board 16 and are turned over to dispose the plate horizontally beneath the box and the core preparatory to the` drawing operation. The latter then is performed by moving the plate and the box vertically away from each other to leave the core resting on the plate.

The improved drawing apparatus comprises generally a support 17 for the core plate 16 and the core and a platform or frame 19 which is disposed above the plate support 17 and which is clamped to the core box 15 during the drawing operation. Relative separating movement between the core plate and the platform is effected in this instance by moving the platform vertically away from the support which is stationary. To facilitate transfer of the core plate and the box onto and away from the plate support, the latter preferably is a part of a conveyor of the type having parallel rollers 1S as shown.

In this instance, the platform 19 is a part of an elevator and comprises two parallel horizontal beams 20 spanned by and secured to opposite ends of two parallel horizontal rails 21 to form a rigid rectangle. At their opposite ends, the beams carry guide collars 22 slidably receiving four stationary upright posts 23 which are disposed on opposite sides of the conveyor 17 and guide the platform for vertical reciprocating movement toward and away from the conveyor. To raise and lower the platform, the collars 22 are secured to the lower ends of cables 24 extending upwardly along the respective posts 23 and wound around two axially spaced drums 25 fast on a horizontal shaft 26. The latter is journaled on and spans the tops of two of the posts at one end of the platform. Each drum receives the cable of the adjacent post and the cable of the remote post on the same side of the platform, the latter cable extending around a pulley 27 journaled on the top of its associated post.

The drum shaft 26 is driven through suitable reduction gearing 23 such as a worm and worm wheel by a reversible electric motor 29 mounted on one of the posts 23 adjacent the shaft and energized through suitable electric circuits (not shown) which are controlled by manually depressible buttons on a control panel 30 (Figs. l and 14) at a control station. When an Up button is depressed, circuits are completed to energize the motor in a direction to wind the cables 24 and raise the platform. The motor rotates in the opposite direction in response to depression of a Down button on the panel. Through suitable holding circuits (not shown) including a switch operated by a Stop button on the panel, each motor energizing circuit remains closed after depression of its associated control button and until the Stop button is depressed. To assist the reduction gearing 2S in holding the drum shaft against turning and the platform against descending when the motor is deenergized, a centrifugally released mechanical brake 31 preferably is employed to apply a retarding torque to the shaft of the motor.

In accordance with the present invention, novel clamping mechanism is provided on the platform 19 to accommodate core boxes 15 of widely differing sizes and shapes and to avoid damage to cores resulting from horizontal shifting of the core boxes While they are being clamped to the platform and raised with the latter away from the cores therein. To these ends, the clamping mechanism comprises a plurality of jaws 32, 33, 34 and 35 mounted on the platform for movement back and forth along horizontally spaced paths and adjustable individually and different distances into engagement with spaced points n opposite sides of a core box 15 supported between the jaws. In the present instance, there are four jaws arranged in two pairs with the jaws of each pair presenting opposed horizontally facing clamping surfaces 36 movable back and forth and toward and away from each other along a path extending longitudinally of the conveyor 17 and parallel to the path of the jaws of the other pair.

To accommodate core boxes of different lengths, the jaws of each pair are mounted on the platform 19 for movement together transversely of the conveyor and toward and away from the other pair of jaws. Such mounting of one pair of jaws 32 and 33 in this instance comprises an elongated carriage 37 spanning the rails 21 and suspended from wheels 38 (Fig. 3) adapted to roll along the tops of the rails. The carriage includes a downwardly opening top channel member 39 (Figs. 5 and 6) and two inwardly opening, horizontally spaced parallel channel members 40 disposed below and secured to the top member as by plates 41 bolted to and projecting laterally from the respective members at spaced points along their length. A horizontal plate 41a spans and is secured as by welding to the bottom walls of the channels 40 intermediate the ends of the latter. The wheels 38 supporting the carriage at each end of the latter are rotatably mounted on two laterally spaced triangular plates 42 (Figs. 1 and 3) upstanding rigidly from the upper side of the top channel member 39 and straddling the adjacent rail 21. A carriage 43 similar to the carriage 37 supports the jaws 34 and 35 of the other pair of jaws.

Movement of the carriages 37 and 43 toward yand away from each other is effected in this instance by a reversible electric motor 44 mounted on one of the platform beams 20 and connected through reduction gearing 45 to a shaft 46 journaled on and spanning the platform rails 21 at one end of the latter. Connecting the shaft 46 and the carriages are two endless flexible chains 47 one extending along the top of each rail and between the spaced carriage plates 42 straddling the latter and each extending around a sprocket 48 fast on the shaft and another sprocket 49 rotatably mounted on the remote end of the associated rail. The lower straight run of each chain is secured to opposite ends of the carriage 37 as by a bolt 50 (Figs. 3 and l1) which extends through a link of the chain and is threaded into a horizontal plate 51 secured to and spanning the upstanding plates 42 above the adjacent rail 21. The upper run of each chain 47 is secured to the carriage 43 in a similar manner by a pin 52 (Figs. l and l2) which extends through a chain link and a plate 53 secured between the upstanding supporting plates of the carriage, this pin being easily removable to permit adjustment of the carriage along the chain run to space the carriages different distances from the center of the platform 19 and lhe conveyor 17 to accommodate irregularly shaped core oxes.

Energization of the motor 44 for rotation in opposite directions -is effected to move the pairs of jaws toward and away from each other through suitable electrical circuits (not shown) in response to the selective depression of a Close clamps button and a Spread clamps button on the control panel 30. Conductors connecting the motor to the control panel are enclosed in a conduit having a flexible section 54 (Fig. 2) extending between the panel and the platform to permit movement of the latter relative to the panel and a rigid section 55 mounted on a pipe 56 which spans the beams 20 and is secured to the latter by brackets 57 (Figs. 1 and 3).

Supporting the jaws 32 and 33 on the carriage 37 are a pair of trolleys or cars 58 having elongated bodies disposed between the inwardly opening channel members 40 with wheels 60 on the sides of the bodies projecting into and adapted to roll along the channel members. Each jaw in this instance is a generally rectangular block slotted vertically on its outer side to receive a portion of a flat leg 61 which depends rigidly from the outer end of the associated trolley body and which is secured as by bolts 62 to the jaw block. For a purpose to appear later, the clamping surface 36 on the inner side of each of the jaws 32 and 33 is yieldable, the surface being defined in this instance by a plurality of blocks 63 of resilient material such as rubber of rectangular cross section seated in horizontal grooves in the jaw block and projecting laterally from the latter. The jaws 34 and 35 are of similar construction and are supported in a similar manner on the other carriage 43.

To insure proper gripping of the core box 15 and clamping thereof to the platform 19 without disturbance of the core caused by shifting of the box horizontally relative to the core plate 16, the clamping force is applied to the jaws 32, 33, 34, and 35 only after the latter have been moved along their respective paths into engagement with opposite sides of the core box. This is accomplished in accordance With the invention by novel power actuated mechanism which is operable rst to apply to each jaw a small force sufficient to shift the same into engagement with the box but insufficient to move the box relative to the core plate 16 and, then, to apply a substantially larger force which is sufficient to clamp the box securely to the platform for movement upwardly with the latter.

Application of such differential forces for individual adjustment of the respective jaws is effected in this instance by a separate power actuated mechanism for each jaw. While both the adjusting and clamping forces may be applied to each jaw by a single power actuator, it is preferred to shift each jaw along its path in response to energization of a small power actuator 64 having a long range of movement and to apply the clamping force to the jaw by energization of a large actuator 65 having a short range of movement.

In this instance, both the small or shifting actuator 64 and the large or clamping actuator 65 for each of the jaws 32, 33, 34, and 35 are fluid pressure operated cylinders, the shifting cylinder having a small bore and corresponding in length to the desired range of jaw movement and the clamping cylinder having a substantially larger bore and short axial length. Each shifting cylinder 64 extends longitudinally of and is secured as by extensions 66 (Figs. 3 and 5) of the plates 41 to the outer side of the carriage for the jaw and has a piston 67 whose rod 68 carries an arm 69 which is secured to the leg 61 supporting the jaw. The two shifting cylinders for each pair of jaws are arranged side by side with their rods 68 extending in opposite directions and are operable when pressure fluid is admitted to their rod ends to advance the jaws toward each other and, when pressure fluid is admitted to their head ends, to retract the jaws.

Fluid, such as air, under pressure is supplied to the shifting cylinders of all four jaws 32, 33, 34, and 35 through the supply pipe 56 which is carried by the platform 19 and which is connected to a suitable source of pressure fluid (not shown) by a flexible hose 70 (Fig. l). Herein, the head and rod ends of the shifting cylinders of each pair of jaws are connected `in parallel (see Fig. 13) and the admission of pressure fluid from the pipe 56 to opposite ends of the shifting cylinders of each pair of jaws is controlled by a solenoid actuated valve 71 (Fig. 13) mounted on the carriage for the jaws and connected to the supply pipe 56 through a exiblc hose 72 (Figs. 1 and 13) which permits movement of the valve with the carriage relative to the pipe. The solenoids of the valves 71 for the shifting cylinders of both pairs of jaws are energized through suitable electrical circuits connecting the solenoids and switches on the control panel 30 and including conductors in the conduit 55 and llexible conduits (not shown) extending between the latter and the carriages 37 and 43. When a Close jaws button on the control panel is depressed, the solenoid valves '7i are actuated to connect the rod ends of the shiftingcylinders to the supply pipe 56 and vent the head ends to the atmosphere to advance the jaws toward each other. To retract the jaws, an Open jaws button on the panel is depressed and the valves are actuated to connect the head ends of the cylinder to the supply pipe and the rod ends thereof to the atmosphere to shift the jaws away from each other.

The use of the clamping cylinder 65 to apply a large clamping force to each jaw after the latter has been moved into engagement with the core box 15 by the shifting cylinder 64 is made possible through the provision of a novel connection 74 (Figs. 4 and 9) between each jaw and the piston rod 75 of its associated clamping cylinder. This connection is selectively engageable and disengageable respectively to transmit the clamping force to the jaw and to permit the latter to be advanced and retracted independently of the clamping cylinder. Herein, the connection comprises pawl and ratchet elements 76 and 77 mounted for movement with the jaw and the piston rod 75 of the clamping cylinder, the pawl being movable into and out of engagement with the ratchet to complete and break the connection.

In this instance, the pawl 76 of each connection 74 is carried by the trolley 58 supporting the jaw and the ratchet 77 is an elongated horizontally disposed bar secured to the piston rod 75 of the associated clamping cylinder 65. The clamping cylinders for the jaws of each carriage are mounted on extensions 78 of the latter (Figs. l, 3, and 4) located at opposite ends thereof and each ratchet bar extends from its cylinder past the adjacent jaw and along the path of the remote jaw whose pawl engages the bar to connect this jaw to the cylinder. Rollers 79 (Figs. 4 and 9) extending transversely of and journaled in each trolley 53 intermediate the ends thereof support the projecting ends of both ratchet bars which are horizontally spaced and lie side by side on the trolley rollers. The teeth t) of each ratchet bar 77 are inclined toward the clamping cylinder for movement of the pawl past the teeth in the advance of the jaw by its shifting cylinder and are formed along the top edge of its associated bar` on the end portion of the latter remote from the clamping cylinder therefor.

Each pawl 76 herein is one end of a lever 81 mounted on its associated trolley 58 for movement of the pawl into and out of an active position of engagement with its ratchet 77 and, when the pawl is in the active position, is yieldably urged toward the ratchet to permit the pawl to move past the ratchet teeth in the advance of the jaw by its shifting cylinder. Such mounting, as shown may comprise a shaft 82 (Figs. 4 to lO) disposed horizontally above the ratchet bars 77 and secured to and extending through spaced parallel plates 83 upstanding rigidly from the trolley car on opposite sides of the ratchet bars, the lever being journaled intermediate its ends on the shaft.

To move each pawl 76 into and out of its active position, the other end S4 of the lever 81 projects upwardly and is engaged by a crosspiece 85 of a U-shaped rocking frame 86 having spaced parallel side legs straddling the upstanding trolley plates and journaled on the projecting ends of the shaft 82. A coiled torsion spring 87 (Fig. 10) encircles the shaft with its ends acting between the crosspiece and the pawl to urge the latter downwardly toward the associated ratchet. When the frame 86 is rocked in a counterclockwise direction as viewed in Figs. 4 and 10, the crosspiece engages the upwardly projecting lever end 84 to shift the pawl to its inactive position above the ratchet. Swinging of the frame in the opposite direction permits the pawl to move downwardly under the action of the spring 87 and into engagement with its ratchet 77 as shown in Fig. 9.

The actuating mechanism for the two pawls 76 on each of the carriages l37 and 43 is simplified by connecting rocking frames 86 for the pawls together in a novel manner for shifting of the pawls in unison by a common actuator 89 regardless of the positions of the trolleys 58 along the jaw paths. For this purpose, one leg of each rocking frame carries a follower element in the form of a roller 90 which is journaled on the rocking frame at a point spaced from the shaft 82 on the side of the latter remote from the pawl and projects laterally from one side of the frame and into an elongated channel member 91 (Fig. 9). The latter extends the full length of the carriage on the inner side of one side wall of the top channel member 39 and is mounted for vertical reciprocation on the wall as by bolts 92 projecting horizontally and rigidly from the channel member 91 and into parallel slots 93 formed in the wall. Herein, the slots are inclined from the vertical and are parallel to the path of reciprocation of the piston rod 94 of a pawl shifting cylinder (Figs. 3 and 9) which is the common actuator 89 for the pawl. This cylinder is secured by a bracket 95 to the top of the carriage. The piston rod 94 is connected by a link 96 to one of the bolts 92 on the channel 91 for shifting of the latter up and down to engage and disengage the pawls 75 when pressure lluid is admitted to the rod and head ends respectively of the cylinder 89.

Means is provided on each carriage to shift the two pawls 76 for the jaws thereon in timed relation to and before energization of the jaw shifting cylinders 64 to insure that the pawls engage their ratchets 77 to complete the connections 74 when the clamping cylinders 65 are energized and to disengage the pawls from the ratchets to break the connections 74 before the shifting cylinders are energized to retract the jaws. Herein, this means comprises restrictions 97 (Fig. 13) located in the fluid pressure supply lines from the valve 7l to both the head and rod ends of each of the two jaw shifting cylinders 64 on each of the -carriages 37 and 43, the head and rod ends respectively of the pawl shifting cylinder 39 being connected in parallel with these same ends of the jaw shifting cylinders 64. Thus, when the valve 7l is actuated to admit pressure fluid to either of the ends of the jaw shifting cylinders and the pawl shifting cylinder, the latter will be energized first due to the restrictions 97 and the pawls will be moved into or out of their active positions of engagement with the ratchets 77 before the jaw cylinders are energized to advance or retract the jaws.

Each clamping cylinder 65 is energized by pressure fluid from the supply pipe 56 and the llow of iluid to opposite ends of the cylinder is controlled by a solenoid actuated valve 98 (Fig. 13) mounted on the associated carriage, the valve being connected between the cylinder ends and the iiexible line 72 from the supply pipe to the carriage. Suitable energizing circuits connect the valve solenoids and the control panel 3d for actuation of the valve to admit pressure tluid to the rod end of the cylinder and vent the head end thereof to atmosphere thereby applying clamping pressure to the jaw when a Clamp button on the panel is depressed. When an Unclamp button is depressed, the valve is actuated to vent the rod end of the cylinder to atmosphere and admit pressure fluid to the head end to release the clamping pressure.

After the jaws 32, 33, 34, and 35 have been shifted into engagement with opposite sides of a core box 15 but before the clamping cylinders 65 are energized, all of the pawls 76 may not be seated completely within the grooves between the teeth 80 of the associated ratchet 77 due to advance of the jaws different distances along their paths. To avoid shifting of the box which might otherwise result when the clamping cylinders of opposed jaws are energized and the ratchets thereof must move different distances for proper seating of the pawls, the supply lines 99 to the rod ends of the two cylinders are connected in parallel by an equalizer line 100 (Fig. 13). With this arrangement, the clamping pressure is applied to the jaws only after both of the associated pawls are seated properly in their ratchets. When the clamping pressure is applied, it is the same for both jaws so that neither can shift the box toward the other.

To facilitate separation of each core box from the core therein without damage to the latter caused by sand sticking to the box walls, the box is vibrated rapidly through a small amplitude as it is raised with the elevator platform 19 and away from the core. Such vibration is effected in this instance by a suitable uid pressure actuated vibrator 101 carried by the platform and engageable with the exterior of a box clamped thereto. Pressure Huid for energizing the vibrator is admitted thereto from the supply pipe 56 through a solenoid valve 102 (see Fig. l) which is actuated through suitable electrical circuits to energize the vibrator in response to depression of a Vibrator button on the control panel 30, the movable member of the valve preferably being spring urged to a closed position for deenergization of the vibrator when the control panel button is released.

Vibration of the elevator platform 19 with the core box 15 when the vibrator 101 is energized. is avoided by providing a yieldable mounting 103 on the platform for the vibrator and by using the blocks 63 to define a yieldable clamping surface 36 on each jaw, the yieldable vibrator mounting and jaw surfaces acting to absorb the vibrations of the core box. The yieldable mounting 103 for the vibrator in this instance comprises two straps of flexible material such as leather clamped at their upper ends to the center of the supply pipe 56 (see Fig. 3) and at their lower ends to the vibrator to suspend the latter in a centered position between the carriages 37 and 43 and the platform rails 21. The straps are of suflicient length that, in the freely suspended position of the vibrator, the bottom thereof is disposed below the undersides of the carriages to engage and rest on the upper side of a core box as the platform is lowered to dispose the jaws on opposite sides of the box.

The extent of motions produced by the various fluid pressure actuators described .above may be positively limited by engagement of the pistons with the ends of the respective cylinders or by the provision of stops coacting with the movable parts. The valves 71 and 98 which control the flow yof pressure fluid to the jaw shifting cylinders 64, the pawl shifting cylinders 89, and the clamping cylinders 65 are so-called 4-way valves whose movable members are actuated by two associated actuating solenoids. In each valve, when one solenoid is energized, the movable valve member is shifted to admit pressure fluid to one end of the associated cylinder and vent the other end of the latter to the atmosphere. The valve member remains in this position until it is shifted by energization of the other solenoid to reverse the connections to the ends of the associated cylinders. The electrical circuits for controlling the energization of the elevator and carriage shifting motors 29 and 44 and the solenoids of the valves 71, 98 and 102 in response to selective depression of the manually depressible buttons on the control panel 30 have been omitted for the purpose of simplifying the disclosure because the manner of interconnection of the parts to be energized and switches controlled by the buttons is well understood in the art.

Operation In the operation of the core box drawing apparatus described above, let it be assumed that the' elevator platform 19 is disposed in an upper retracted position and the carriages 37 and 43 have been separated as shown in phantom in Fig. l with the jaws 32, 33, 34 and 35 fully retracted and the pawls 76 raised in their inactive positions as shown in Figs. 4, 5 and 6. After a core plate 16 with a core and a core box 15 thereon has been moved along the conveyor 17 and centered approximately relative to and below the platform, the motor 29 is energized in the proper direction to lower the platform by depressing the Down button on the control panel 30. When the platform has reached a lower position in which the under sides of the carriages 37 and 43 are slightly higher than the upper side of the core box and the vibrator 101 is resting on the latter with the straps 103 slackened, the descent of the platform is stopped by depressing the Stop button to interrupt the holding circuit to the motor.

Next, the carriage shifting motorv 44 is energized by depressing the Close clamps button to move the carriages 37 and 43 toward each other across the upper side of the core box and into positions adjacent the ends ofthe box as shown in Fig. l. The Close clamps button then is released to interrupt the energizing circuit for the motor 44 and the Close jaws button is depressed to actuate the solenoid valves 71 to admit pressure uid to the rod ends of the pawl shifting and jaw shifting cylinders 64 and 89. As a'result, the channel bars 91 are raised to swing the rocking frames 86 about the shafts 82 to permit the pawls 76 to move into engagement with the ratchets 77 under the action of the springs 87. After a short delay due to the restrictions 97 in the supply lines of the jaw shifting cylinders 64, the latter are energized to move the jaws inwardly toward each other and into engagement with opposite sides of the core box. Since the jaws are adjustable different distances along their paths, they can accommodate boxes which vary widely in size, which .are of irregular shape, or which, if of regular shape, are located beneath the platform in an off-center position or with their opposed walls canted away from a normal to the jaw paths. The application of .a small shifting force to the jaws by the cylinders 64 permits the jaws to be positioned properly against the box without moving the latter relative to the core plate. With cylinders of 11A inches diameter and with air pressure of around pounds per square inch, the force applied to each jaw by its shifting cylinder 64 is approximately pounds.

After the jaws 32, 33, 34 and 35 have been advanced against opposite sides of the core box 15 by a small force, the Clamp button is depressed to energize the clamping cylinders and apply a substantially larger force to the jaws to clamp the box rigidly to the platform 19. Since the rod ends of the clamping cylinders of each pair of jaws are connected by the equalizer line 100, such clamping of the box to the platform is effected without moving the box. The force applied to each jaw by its clamping cylinder in this instance is approximately 1700 pounds.

With the box clamped to the platform 19, the Up button is depressed to energize the elevator motor 29 for raising the platform. Just before the Up button is depressed, the vibrator 101 is actuated in response to depression of the Vibrator button, the latter being held down until the core box clears the core and then being released. When the platform has moved high enough to permit removal of the core plate and core, the Stop button is depressed to deenergize the elevator motor and stop the ascent of the platform.

As soon as the core plate 16 and core thereon have been moved along the conveyor 17 and out from beneath the platform, the Down button is depressed and the platform descends until the core box is disposed just above the conveyor. At this time, the Stop button is depressed to stop the platform and the Unclamp button is pressed to actuate the valves 98 and release the clamping pressure on the jaws, thereby permitting the core box to drop onto the conveyor. The latter then are separated by depressing the Open jaws button to actuate the valves 71 for admission of pressure uid to the head ends of the pawl shifting and jaw shifting cylinders 64 and 89. By virtue of the restrictions 97 in the supply lines of the jaw shifting cylinders, the pawl shifting cylinders 89 are energized to lower the channel bars 91 and raise the pawls 76 out of engagement with the ratchets 77 to break the connections 74 before the jaw cylinders 64 are energized to retract the jaws. While the jaws are moving to their retracted positions, the Up button is depressed to raise the platform to its upper idle position where the Stop button is pressed to deenergize the elevator motor. After the drawn core box has been pushed along the conveyor 17 and away from the platform, the apparatus is in condition to perform another drawing operation.

I claim as my invention:

1. Core box drawing apparatus having, in combination, a horizontally disposed frame, a pair of horizontally spaced carriages on said frame, a pair of clamping jaws mounted on one of said carriages for movement toward and away from and independently of each other along a first horizontal path and individually into engagement with a core box supported between the jaws, a second pair of clamping jaws similarly mounted on the other of said carriages to move toward and away from and independently of each other along a second path parallel to and horizontally spaced from said rst path, two separate power actuated means one carried by each of said carriages and each connected to the jaws thereon to advance the same individually into clamping engagement with oppositely facing sides of the core box, and means on said frame mounting said carriages for horizontal movement of said pairs of jaws relative to and toward and yaway from each other transversely of said jaw paths to accommodate core boxes of different lengths.

2. Core box drawing mechanism having, in combination, a horizontally disposed frame, a plurality of clamping jaws arranged in pairs, means mounting said jaws on said frame for movement of the jaws of each pair individually and different distances along a path extending longitudinally of and horizontally spaced from the path of the other pair of jaws, said mounting means including a carriage supporting at least one of the pairs of jaws and shiftable transversely of said paths for movement of the pair of jaws thereon toward and away from the other pair, and power actuated means acting between said frame and said jaws and operable to advance the jaws individually different distances into clamping engagement with oppositely facing surfaces of a core box supported between the jaws of both of said pairs.

3. Core box drawing mechanism having, in combination, a horizontally disposed frame, a pair of opposed clamping jaws mounted on said frame for individual movement different distances toward and away from each other along a rst generally horizontal path, a second similar pair of jaws mounted on said frame for individual movement different distances toward and away from each other along a second path extending longitudinally of and spaced horizontally from said rst path, anda plurality of power actuators each acting between said frame and a different one of said jaws and individually operable to advance the associated jaw into clamping engagement with one side of a core box supported below said frame and between the jaws of each of said pairs, said jaws advancing different distances to accommodate core boxes of different sizes and shapes.

4. Core box drawing mechanism having, in combination, a horizontally disposed frame, a pair of opposed jaws each mounted on said frame for movement independently of the other jaw toward and away from the latter along a rst generally horizontal path, a second similar pair of jaws mounted on said frame for movement toward and away from and independently of each other along a second path extending longitudinally of and spaced horizontally from said rst path, and power actuated means acting between said frame and each of said jaws and operable to advance the latter individually and different distances into clamping engagement with opposite sides of core boxes to accommodate boxes of different sizes and shapes supported below said frame and between the jaws of both of said pairs.

5. In apparatus for drawing core boxes, the combination of, a frame, a pair of clamping jaws mounted on said frame for movement toward and away from each other along a predetermined path, power actuated means acting between said jaws and said frame and operable to advance and retract the jaws along said path and into and out of engagement with a core box supported between the jaws, two power actuators one for each of said jaws and each acting between the associated jaw and said frame to apply an advancing force to the jaw substantially greater than that applied by said power actuated means, a disengageable connection between each of said actuators and its associated jaw including pawl and ratchet elements carried by the jaw and the actuator and cooperating to permit advance of the jaw while preventing retraction thereof relative to the actuator when the elements are engaged, a single power actuated member engageable with both of saidpawl elements and shiftable back and forth selectively to move the pawl elements together into and out of engagement with the respective ratchet elements and thereby engage and disengage said connection, and means responsive to actuation of said member and operable to energize said power actuated means to retract said jaws in timed relation to shifting of the member and after said pawl elements have been disengaged from said ratchet elements.

6. In apparatus for drawing core boxes, the combination of, a frame, a pair of clamping jaws mounted on said frame for movement toward and away from each other along a predetermined path, power actuated means acting between said jaws and said frame and operable to advance and retract the jaws along said path and into and out of engagement with a core box supported between the jaws, two power actuators one for each of said jaws and each acting between the associated jaw and said frame to apply an advancing force to the jaw substantially greater than that applied by said power actuated means, a disengageable connection between each of said actuators and its associated jaw including pawl and ratchet elements carried by the jaw and the actuator and cooperating to permit advance of the jaw while preventing retraction thereof relative to the actuator when the elements are engaged, and a single power actuated member engageable with both of said pawl elements and shiftable back and forth selectively to move the pawl elements simultaneously into and out of engagement with the respective ratchet elements and thereby engage and disengage said connection.

7. In apparatus for drawing core boxes, the combination of, a frame, a clamping jaw mounted on said frame for movement back and forth along a predetermined path, a first power actuator acting between said frame and said jaw and operable to advance and retract the latter along said path, a second power actuator acting between said frame and said jaw and operable when energized to apply an advancing force to the latter substantially larger than the force applied by said first actuator, a disengageable connection between=said jaw and said second actuator including pawl and ratchet elements carried by the jaw and the actuator and cooperating to permit advance of the jaw while preventing retraction thereof relative to the actuator when the elements are engaged, a power actuated member engageable with said pawl element and operable selectively to shift the latter out of engagement with said ratchet element to disengage said connection to permit retraction of said jaw, and means responsive to actuation of said member and operable to energize said first power actuator to retract said jaw in timed relation to shifting of said pawl element and after the latter is disengaged from said ratchetv element.

8. In apparatus for drawing core boxes, the combination of, a frame, a clamping jaw mounted on said frame for movement back and forth along a predetermined path, a first power actuator acting between said frame and said jaw and operable to advance and retract the latter along said path, a second power actuator acting between said frame and said jaw and operable when energized to apply an advancing force to the latter substantially larger than the force applied by said rst actuator, the line of action of said second actuator extending parallel to said path, a disengageable connection between said jaw and said second actuator including pawl and ratchet members carried by the jaw and the actuator and cooperating to permit advance of the jaw while preventing retraction thereof relative to the actuator when the members are engaged, and means engageable with said pawl member and operable selectively to move the latter out of engagement with said ratchet member to permit retraction of said jaw.

9. In apparatus for drawing core boxes, the combination of, a frame, a clamping jaw carried by said frame and guided for movement along a predetermined path and back and forth between a retracted position and a spaced advanced position of engagement with a core box supported adjacent the frame, a reversible power actuator acting between said frame and said jaw and adapted when energized to apply a relatively small force to the jaw to shift the same along said path between said positions, a second power actuator having a shorter range of movement than said reversible actuator and operable when energized and when said jaw is in said advanced position to apply a larger force to said jaw and clamp the same rigidly against said box, the line of action of said second actuator extending parallel to said path, a disengageable connection between said second actuator and said jaw, and means for engaging said connection to enable said larger clamping force to be applied by said second actuator after said jaw has been shifted to said advanced position and for disengaging the connection to permit the jaw to be shifted out of the advanced position by said reversible actuator.

10. In apparatus for drawing core boxes, the combination of, a frame, at least one pair of clamping jaws mounted on said frame and movable horizontally toward and away from and independently of each other and into and out of engagement with opposite sides of a core box supported between the jaws, power actuated means on said frame acting between the latter and said jaws and operable when energized to shift each jaw individually toward the other jaw, and means for energizing said power actuated means first to apply a small force to each of said jaws to advance the same individually into engagement with said box without shifting the latter on its support, and other means for energizing said power actuated means to apply a substantially larger force to said jaws simultaneously to clamp the box rigidly between the jaws.

ll. Core box drawing mechanism having, in combination, a horizontally disposed frame, a pair of jaws mounted on said frame for movement toward and away from each other along a generally horizontal path and having opposed clamping faces of yieldable material facing along said path, power actuated means mounted on said frame and connected to said jaws to shift the latter along said path and said yieldable faces thereof into clamping engagement with opposite sides of a core box supported between the jaws, a exible element suspended from said frame above said jaw path, and a power actuated vibrating device secured to the lower end of said exible element and disposed between said jaws to engage with the top of a core box clamped between the jaws, said yieldable material of said clamping faces and said flexible element cooperating to absorb the vibration resulting from energization of said device and avoid transfer thereof to said frame.

12. The combination defined in claim 10 in which said power actuated means includes two separate pressure uid actuators each operable to advance a dilerent one of said jaws and said other energizing means includes a common pressure uid connection between the actuators.

References Cited in the le of this patent UNITED STATES PATENTS 1,869,112 Nichols July 26, 1932 2,047,105 Kline July 7, 1936 2,105,877 Carney Jan. l8, 1938 y2,278,190 Bodi Mar. 31, 1942 2,289,140 Mohan July 7, 1942 2,545,799 Snow Mar. 20, 1951 2,581,418 Kohl Jan. 8, 1952 2,609,954 Sutherland et al Sept. 9, 1952 2,615,747 Olson Oct. 28, 1952 2,680,270 Gedris June 8, 1954 

